一对多双向关联的注解实现 及 复合主键

现有DashboardWindow 和 DashboardWinParam 两个实体，是父子关系

DashboardWindow（一端）：
@Entity
@Table(name="SYS_DASHBOARD_WINDOW")
public class DashboardWindow {//corresponding to APPData
@Id
@Column(name="WIN_ID")
@GenericGenerator(name = "WIN_ID", strategy = "assigned")
private long id;
@Column(name="WIN_NAME",length=30)
private String name;
@Column(name="WIN_STATUS")//0-Normal  1-Min  2-Max 
private int status;
@Column(name="WIN_INDEX")
private int index;
@Column(name="DASHBOARD_ID")
private long parentDsbId;
@Column(name="WIN_X")
private int winX;
@Column(name="WIN_Y")
private int winY;
@Column(name="WIN_HEIGHT")
private int winHeight;
@Column(name="WIN_WIDTH")
private int winWidth;
@Column(name="APP_URL",length=255)
private String appUrl;
@Column(name="MODIFY_DATE")
private Timestamp modifyDate;

@OneToMany(mappedBy="dashboardWindow",cascade={CascadeType.ALL},fetch=FetchType.EAGER)
private Set dashboardWinParams; 

public Set getDashboardWinParams() {
if(dashboardWinParams == null){
dashboardWinParams = new HashSet();
}
return dashboardWinParams;
}
public void setDashboardWinParams(Set dashboardWinParams) {
this.dashboardWinParams = dashboardWinParams;
}
public long getId() {
return id;
}
public void setId(long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getIndex() {
return index;
}
public void setIndex(int index) {
this.index = index;
}
public int getStatus() {
return status;
}
public void setStatus(int status) {
this.status = status;
}
public long getParentDsbId() {
return parentDsbId;
}
public void setParentDsbId(long parentDsbId) {
this.parentDsbId = parentDsbId;
}
public int getWinX() {
return winX;
}
public void setWinX(int winX) {
this.winX = winX;
}
public int getWinY() {
return winY;
}
public void setWinY(int winY) {
this.winY = winY;
}
public int getWinHeight() {
return winHeight;
}
public void setWinHeight(int winHeight) {
this.winHeight = winHeight;
}
public int getWinWidth() {
return winWidth;
}
public void setWinWidth(int winWidth) {
this.winWidth = winWidth;
}
public String getAppUrl() {
return appUrl;
}
public void setAppUrl(String appUrl) {
this.appUrl = appUrl;
}
public Timestamp getModifyDate() {
return modifyDate;
}
public void setModifyDate(Timestamp modifyDate) {
this.modifyDate = modifyDate;
}

}


 


DashboardWinParam（多端）: 




通过@IdClass注释在实体中标注复合主键.
@Entity
@Table(name="SYS_DASHBOARD_WIN_PARAM")
@IdClass(PKWinParam.class)
public class DashboardWinParam {
private String name;
private String value;//default value 
private DashboardWindow dashboardWindow;

@Id
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Column(name="PARAM_VALUE",nullable=false,length=255)
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
@Id
public DashboardWindow getDashboardWindow() {
return dashboardWindow;
}
public void setDashboardWindow(DashboardWindow dashboardWindow) {
this.dashboardWindow = dashboardWindow;
}


}








PKWinParam(嵌入的主键类，用于复合主键)：


@JoinColumn(name="WIN_ID") 表明DashboardWinParam的外键WIN_ID，指向DashboardWindow的主键列 WIN_ID


@Embeddable
public class PKWinParam implements Serializable {

private DashboardWindow dashboardWindow;
private String name;


@ManyToOne(cascade={CascadeType.PERSIST,CascadeType.MERGE})
@JoinColumn(name="WIN_ID",referencedColumnName="WIN_ID",nullable=false)
public DashboardWindow getDashboardWindow() {
return dashboardWindow;
}


public void setDashboardWindow(DashboardWindow dashboardWindow) {
this.dashboardWindow = dashboardWindow;
}


@Column(name="PARAM_NAME",nullable=false,length=50)
public String getName() {
return name;
}


public void setName(String name) {
this.name = name;
}


@Override
public boolean equals(Object o) {
if (this == o)
return true;
if (o == null)
return false;
if (!(o instanceof PKWinParam))
return false;
PKWinParam pk = (PKWinParam) o;
if (this.dashboardWindow.getId() == pk.getDashboardWindow().getId() && this.name.equals(pk.getName())) {
return true;
}
return true;
}


@Override
public int hashCode() {
return 31 * this.dashboardWindow.hashCode() + this.name.hashCode();
}
}